1. Field of the Invention
The present invention relates to the field of biochemical labeling materials. More particularly, the invention relates to a biochemical labeling material comprising molecularly imprinted nanoparticles.
2. Description of the Related Art
For an eligible biochemical labeling material, two properties are important; selectivity of analytes, and effectiveness of signals produced after biochemical labeling, with resultant ease of detection.
Conventional biochemical labeling materials utilize the unique selectivity of antibody to antigen to enhance effectiveness. For example, peptide and other proteins are used as polyclonal antibodies that select the analyte via adsorption. Fluorescent reagents are applied to produce “labeled” signals in terms of variations of wavelength and intensity of fluorescence.
As nanotechnology develops, semiconductor-nanocrystals are used as fluorescent probes in biochemical labeling materials. Compared to conventional biochemical labeling materials producing weaker, more difficult-to-observe signals, fluorescent probes of semiconductor-nanocrystals, owing to their narrower energy gap, produce stronger signals and more stable fluorescence, adjustable in different situations for different analytes.
Surface functionalization is performed on most semiconductor-nanocrystals prior to usage as biochemical labeling materials. First, II-IV or III-V group semiconductor-particles (single-semiconductor particles or core-shell particles composed of two semiconductors) are reacted with mercaptoacetic acid to form carboxylic groups attached thereon such that the particles become hydrophilic. Then, proteins are attached to the functionalized particles by covalent bonding. Proteins are polyclonal antibodies able to identify the analyte (i.e. antigen). Once the analyte attaches thereon, the quantum effect of nanocrystal particles generates the signals.
Bruchez et al, in Semiconductor-Nanocrystals as Fluorescent Biological Labels (Science 281, 2013 (1998)) modify the third Si layer of CdSe—CdS core-shell semiconductor-nanocrystal particles to be hydrophilic, and then re-modify the Si layer by different functional group to become reactive with biochemical substances. Different modification by Si is performed to increase quantum effect and improve properties. Different core-shell semiconductor-nanocrystal particles were studied, with the main purpose thereof being the fluorescent labeling of mouse fibroblast cells.
Chen et al (Quantum Dot Bioconjugates for Ultrasensitive Nonisotopic Detection, Science 281, 2016 (1998)) study high-fluorescence-semiconductor quantum dot (Zinc Sulfide-capped cadmium selenide) to bond biochemical molecules by covalent bonds and applied to super-high sensitive biochemical labeling materials. Compared to organic dyes, e.g. rhodamine, the intensity of fluorescence increases 20 times, the stability to photobleaching increases 100 times that, but the Spectrum line width is only ⅓ thereof. The manufacturing method thereof uses ZnS-capped CdSe as the quantum dot, modify the surface by mercaptoacetic acid, and bond with proteins by carboxylic groups.
Tan et al (U.S. Pat. No. 6,548,264) manufacture Ag or Cd semiconductor-nanoparticles by microemulsion and react them with silicate to form a layer of silicate, and a silicate layer is modified to bond with proteins, antibody, or antigen.
Mirkin et al (WO Patent 2001073123  2001051665  9804740) synthesize nanoparticle-oligonucleotide conjugates to detect nucleic acid by the color change owing to combination thereof.
Ewart et al (WO Patent 9821587) synthesize omit-human IgG-alkaline phosphatase conjugate ZnS:Cu:Aλ capped fluorescent nanoparticles as label materials.
Nanoparticles have thus far been utilized in manufacture of biochemical labeling materials as discussed above, however, the identifying ability of proteins is limited to certain biochemical substrances, and modification of multilayer-nanocrystal particles broadens of Emission Spectrum and instability of photochemical properties.